Biomedical Engineering and Bioengineering Commons^™

Patient-Derived Hydrogel As A Sacrificial Matrix For Efficient Cell Loading, Shalmli U. Joshi

Honors Scholar Theses

The field of tissue engineering focuses on delivering patient-derived stem cells to the body through the use of degradable biomaterials, such as hydrogels, which are infused into engineered scaffolds. Hydrogels act as templates to support and guide cells towards the regeneration of new tissue. In this study, we introduce a completely intraoperative procedure for obtaining a fibrin hydrogel for tissue engineering applications. In the past, fibrin hydrogel has been commonly formed by combining fibrinogen protein with animal-derived thrombin. Instead, we have developed an automated, and therefore reproducible, protocol to isolate and form fibrin hydrogel without the use of animal-derived thrombin. …

Exploiting Self-Organization In Bioengineered Systems: A Computational Approach, Delin Davis, Anna Doloman, Gregory J. Podgorski, Elizabeth Vargis, Nicholas S. Flann

Biological Engineering Faculty Publications

The productivity of bioengineered cell factories is limited by inefficiencies in nutrient delivery and waste and product removal. Current solution approaches explore changes in the physical configurations of the bioreactors. This work investigates the possibilities of exploiting self-organizing vascular networks to support producer cells within the factory. A computational model simulates de novo vascular development of endothelial-like cells and the resultant network functioning to deliver nutrients and extract product and waste from the cell culture. Microbial factories with vascular networks are evaluated for their scalability, robustness, and productivity compared to the cell factories without a vascular network. Initial studies demonstrate …

Optimization Of Fluorescent Imaging In The Operating Room Through Pulsed Acquisition And Gating To Ambient Background Cycling, Kristian J. Sexton, Yan Zhao, Scott C. Davis, Shudong Jiang, Brian Pogue

Dartmouth Scholarship

The design of fluorescence imaging instruments for surgical guidance is rapidly evolving, and a key issue is to efficiently capture signals with high ambient room lighting. Here, we introduce a novel time-gated approach to fluorescence imaging synchronizing acquisition to the 120 Hz light of the room, with pulsed LED excitation and gated ICCD detection. It is shown that under bright ambient room light this technique allows for the detection of physiologically relevant nanomolar fluorophore concentrations, and in particular reduces the light fluctuations present from the room lights, making low concentration measurements more reliable. This is particularly relevant for the light …

Sophorolipid Butyl Ester Diacetate Does Not Affect Macrophage Polarization But Enhances Astrocytic Glial Fibrillary Acidic Protein Expression At Micromolar Concentrations In Vitro, Alexis M. Ziemba, Manoj K. Gottipati, Filbert Totsingan, Cheryl M. Hanes, Richard A. Gross, Michelle R. Lennartz, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Peritoneal macrophages (PMACs) and spinal cord astrocytes were exposed to varying concentrations of soluble sophorolipid butyl ester diacetate (SLBEDA) in vitro. Macrophages and astrocytes demonstrated no decrease in viability in response to SLBEDA. Studying pro- and anti-inflammatory genes, PMACs did not show a shift toward a pro-inflammatory phenotype. However, at higher concentrations (3 and 30 μM), astrocytes showed an increase in their expression of glial acidic fibrillary protein. This novel category of compounds poses low risk to PMAC and astrocyte viability; however, the effect on PMAC polarization and astrocyte reactivity requires more elucidation.

Brain Lesions Among Orally Fed And Gastrostomy-Fed Dysphagic Preterm Infants: Can Routine Qualitative Or Volumetric Quantitative Magnetic Resonance Imaging Predict Feeding Outcomes?, Nasser H. Kashou, Irfaan Akram Dar, Mohamed A. El-Mahdy, Charles Pluto, Mark Smith, Ish K. Gulati, Warren Lo, Sudarshan R. Jadcherla

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Introduction: The usefulness of qualitative or quantitative volumetric magnetic resonance imaging (MRI) in early detection of brain structural changes and prediction of adverse outcomes in neonatal illnesses warrants further investigation. Our aim was to correlate certain brain injuries and the brain volume of feeding-related cortical and subcortical regions with feeding method at discharge among preterm dysphagic infants.

Materials and methods: Using a retrospective observational study design, we examined MRI data among 43 (22 male; born at 31.5 ± 0.8 week gestation) infants who went home on oral feeding or gastrostomy feeding (G-tube). MRI scans were segmented, and volumes of brainstem, …

Shear Driven Micro-Fluidic Pump For Cardiovascular Applications, Nihad E. Daidzic

Aviation Department Publications

A valveless shear-driven micro-fluidic pump design (SDMFP) for hemodynamic applications is presented in this work. One of the possible medical and biomedical applications is in-vivo hemodynamic (human blood circulation) support/assist. One or more SDMFPs can be inserted/implanted into vascular lumens in a form of a stent/duct in series and/or in parallel (bypass duct) to support blood circulation in-vivo. A comprehensive review of various micro-pump designs up to about mid 2000’s is given in [1,2]. Many of micropump designs considered are not suitable for in-vivo or even in-vitro medical/biomedical applications.

Operating principles, design, and SDMFP features are given in [3]. A …

Method And Shear-Driven Micro-Fluidic Pump, Nihad E. Daidzic

Aviation Department Publications

United States Patent Application, Publication Number US 2017/0096990 A1, Publication Date April 6, 2017.

An example includes an apparatus to pump a fluid. The apparatus includes a housing extending along a length defining an elongate interior, an actuator in the housing, conforming to the elongate interior, the actuator including a plurality of lumens, each having a length extending substantially parallel to the elongate interior, each from around 10 to 200 micrometers across and an actuator configured to oscillate the actuator in the actuator housing along the length of the elongate interior with a rate differential between movement in a first …

Exploring Therapeutic Approaches For Marfan Syndrome Associated Aortic Aneurysm, Mitra Esfandiarei

Science Seminar Series

Esfandiearei will be discussing her research on understanding the underlying mechanisms contributing to the progression of aortic aneurysm in Marfan syndrome and the protective effects that exercise may have on the disease process in both laboratory animal models and human patients. Her research has been supported by the Canadian Institutes of Health Research (CIHR), Rare Diseases Foundation, and the Marfan Foundation.

Neuropeptide Modulation Of The Large Conductance Potassium (Bk) Channel In The Auditory System: Therapeutic Implications For Age-Related Hearing Loss, Ellliott James Brecht

USF Tampa Graduate Theses and Dissertations

The auditory temporal processing deficits associated with age-dependent hearing decline have been increasingly attributed to issues beyond peripheral hearing loss. Age-related hearing loss (ARHL), also known as presbycusis, is linked with changes in the expression of both excitatory and inhibitory neurotransmitters in the central auditory system. There are also age-related changes in the expression and function of the ion channels which mediate action potential firing. The slow, Ca²⁺ activated, K⁺ channels of the BK-type are essential in controlling both neurotransmitter release and neural communication via alteration of action potential durations, firing frequency, and neural adaptation. There are many …

A Novel Biochamberfor Modeling Of Atherosclerotic Arteries: In Vitro Capabilities And Applications, Iman Salafian, Angelos Karagiannis, Benjamin S. Terry, Yiannis S. Chatzizisis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is a chronic disease that involves the lipid accumulation and inflammation of the arterial wall [1,2]. Despite great efforts,its pathophysiology has not been fully elucidated. Existent drugs can reduce its progression but there are no available drugs to prevent its complications [3,4]. Atherosclerosis remains the leading global cause of death[5].

The purpose of this work is to design and build a customized biochamber which can be used for the following studies:

•Study the pathophysiology of atherosclerosis in vitro & ex vivo

•Investigate the mechanisms of atherosclerotic plaque disruption

•Examine the direct effect of different anti-atherosclerotic drugs on lesions

•Use …

Chemical And Physical Priming Of Human Mesenchymal Stem Cells To Alter Nonviral Gene Delivery Outcomes, Tyler Kozisek, Andrew Hamann, Amy Mantz, Mathias Schubert, Eva Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Human Mesenchymal Stem Cells: Human mesenchymal stem cells (hMSCs) are a multipotent cell, meaning they are able to differentiate into a more mature cell type, such as osteocytes, chondrocytes, and adipocytes, that are found in numerous tissues in the human body, such as bone marrow, fat, and muscle. Since hMSCs can be derived from adult human tissues, they do not have the same ethical concern associated with them as other stem cells, such as embryonic stem cells. Due to hMSCs multipotency and ease of obtaining, they have become one of the most widely researched stem cell types in areas such …

A Drosophila Model To Examine Collective Migration During Retinogenesis, Caroline Pena, Stephanie Zhang, Mildred Kamara, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

Retinal dysfunction is often caused by aberrant neural cell migration during development. In this study, we observed the migration of neural cells of the Drosophila melanogaster after marking cells of the 3rd instar larvae with the GAL4-UAS expression system when exposed to a concentration gradient of FGF-8 through the use of a microfluidic device. The glial and neuronal cell ratio in the developing brain was determined through immunofluorescent staining and observation. In future studies, a microfluidic device that mimics the developing Drosophila brain and retina will be designed in order to better understand the biological factors that affect the migration …

Department Of Biological Systems Engineering Newsletter, Spring 2017

BSE Department Magazine

No abstract provided.

Improvement Of Fluorescence-Based Microfluidic Dna Analyzers, Collin Tranter

Doctoral Dissertations

A tremendous effort continues in the development of micro-total-analysis-systems; in support of this, many chemical passivation methods have been developed to enhance the biocompatibility of such microfluidic systems. However, the suitability of these passivation techniques to many fluorescence-based assays still remains inconsistent. This part of this work is focused on the performance of a third generation intercalating DNA dye when used within microfluidic devices treated with a select variety of passivating coatings. The results of these tests indicate that passivation coatings which are intended to shed DNA based on electrostatic repulsion will in fact imbibe the fluorescent DNA intercalating dye …

Amending Phb With Algal Biomass To Enhance Biodegradability, Amanda R. Stoudt

Undergraduate Honors Capstone Projects

Pollution due to petroleum-based plastic is a growing problem all over the world. Petroleum-based plastics that fill landfills and oceans take hundreds of years to degrade. One possible solution to this growing problem is to increase the use of bioplastics. Polyhydroxybutyrate (PHB) is a widely studied bioplastic that is biodegradable in both soil and marine environments. However, PHB use is limited due to its poor mechanical properties. Past researchers have investigated the use of natural additives, primarily different types of plant fibers, to enhance both the mechanical properties and degradation rates of bioplastics. The purpose of this project was to …

Electrospun Spiderskin Bandage For Epidermal Protection And Recovery, Michael David Paskett

Undergraduate Honors Capstone Projects

Spider silk is one of nature's most promising biomaterial s for a variety of applications, however, due to the inability to farm spiders, transgenic hosts are required for large-scale production. With the unique combination of strength, elasticity, and biocompatibility, spider silk has an incredible potential for use in the human body. This study was conducted to merge two major applications of spider silk for the creation of a novel bandaging product. Electrospinning technology was utilized to create a spider silk/polymer bandage matrix to be applied with an aqueous spider silk skin adhesive.

In designing the bandaging matrix , the mechanical …

A Balanced Approach To Adaptive Probability Density Estimation, Julio Kovacs, Cailee Helmick, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

Our development of a Fast (Mutual) Information Matching (FIM) of molecular dynamics time series data led us to the general problem of how to accurately estimate the probability density function of a random variable, especially in cases of very uneven samples. Here, we propose a novel Balanced Adaptive Density Estimation (BADE) method that effectively optimizes the amount of smoothing at each point. To do this, BADE relies on an efficient nearest-neighbor search which results in good scaling for large data sizes. Our tests on simulated data show that BADE exhibits equal or better accuracy than existing methods, and visual tests …

Clinical Applications Of Near-Infrared Diffuse Correlation Spectroscopy And Tomography For Tissue Blood Flow Monitoring And Imaging, Yu Shang, Ting Li, Guoqiang Yu

Biomedical Engineering Faculty Publications

Objective. Blood flow is one such available observable promoting a wealth of physiological insight both individually and in combination with other metrics.

Approach. Near-infrared diffuse correlation spectroscopy (DCS) and, to a lesser extent, diffuse correlation tomography (DCT), have increasingly received interest over the past decade as noninvasive methods for tissue blood flow measurements and imaging. DCS/DCT offers several attractive features for tissue blood flow measurements/imaging such as noninvasiveness, portability, high temporal resolution, and relatively large penetration depth (up to several centimeters).

Main results. This review first introduces the basic principle and instrumentation of DCS/DCT, followed by presenting …

Repair And Regeneration Of Chondral Defects: An In Vitro Study Demonstrating Feasibility And Mechanism Under Low Intensity Ultrasound, Neety Sahu, Anuradha Subramanian

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Holistic repair of damaged cartilage remains an unsolved biomedical problem. Current methods that employ microfracture (MF) or autologous chondrocyte implantation (ACT) or tissue engineered strategies yield inferior repaired cartilage (Fig. 1). Lack of chondroinductive factors at the site of injury, in vivo, has been identified as a factor that limits repair. Clinically amenable strategies that can improve repair are desired. A novel clinically translatable repair strategy based on low-intensity-ultrasound (US) is proposed (Fig.2). Differently from all approaches that use US, our approach employs US at the cell resonant frequency where bioeffects are maximized. We have shown that US impacts the …

White Matter Hyperintensity Associations With Cerebral Blood Flow In Elderly Subjects Stratified By Cerebrovascular Risk, Ahmed A. Bahrani, David K. Powell, Guoqiang Yu, Eleanor S. Johnson, Gregory A. Jicha, Charles D. Smith

Biomedical Engineering Faculty Publications

Objective: This study aims to add clarity to the relationship between deep and periventricular brain white matter hyperintensities (WMHs), cerebral blood flow (CBF), and cerebrovascular risk in older persons. Methods: Deep white matter hyperintensity (dWMH) and periventricular white matter hyperintensity (pWMH) and regional gray matter (GM) and white matter (WM) blood flow from arterial spin labeling were quantified from magnetic resonance imaging scans of 26 cognitively normal elderly subjects stratified by cerebrovascular disease (CVD) risk. Fluidattenuated inversion recovery images were acquired using a high-resolution 3-dimensional (3-D) sequence that reduced partial volume effects seen with slicebased techniques. Results: dWMHs but not …